The Kaleido 3 screen that most of these color e-readers use was released in 2022. No new advancements since then in this space. Kinda sad but these are being out-competed by tablets. Seems that this tech is being developed thanks to signage screens as the color e-reader market is too small.
The new PocketBook Era Color e-reader has just been launched. In addition to a 7-inch E Ink Kaleido 3 color screen, it also features audiobook support and a text-to-speech function.